Linear ethylene polymers, particularly linear low density polyethylene (LLDPE) are widely used commercially in films. The films are conventionally prepared by blown film extrusion and have generally good properties. Considerable effort has been devoted to improving one or more of the physical properties by blending the LLDPE with other resins, or by other means. For example, U.S. Pat. No. 4,579,912, which is incorporated by reference, discloses the use of polystyrene or poly(para-methylstyrene) to improve tear strength. It was subsequently found that the addition of polystyrene resin also improved the blocking characteristics and reduced the splittiness as measured by machine direction puncture propagation of the film making it particularly suitable for bags and the like.
In a separate body of research, as disclosed in U.S. Pat. No. 3,383,435, which is also incorporated by reference, it was discovered that the excellent physical properties of polyphenylene oxide (PPO) resins can be largely retained but that its processability can be improved significantly by blending with polystyrene. Thus, U.S. Pat. No. 3,383,435 discloses blends of 1 to 99 weight percent polyphenylene oxide and 1 to 99 weight percent of a styrene resin which is a resin containing 25 percent or more of styrene or a substituted styrene.
This invention is based on the discovery that blending linear polyethylene with a mixture of polyphenylene oxides (PPO) and a styrene resin as disclosed in U.S. Pat. No. 3,383,435, gives a composition having excellent impact strength.